Modular heat-transfer systems

ABSTRACT

Some modular heat-transfer systems can have an array of at least one heat-transfer element being configured to transfer heat to a working fluid from an operable element. A manifold module can have a distribution manifold and a collection manifold. A decoupleable inlet coupler can be configured to fluidicly couple the distribution manifold to a respective heat-transfer element. A decoupleable outlet coupler can be configured to fluidicly couple the respective heat-transfer element to the collection manifold. An environmental coupler can be configured to receive the working fluid from the collection manifold, to transfer heat to an environmental fluid from the working fluid or to transfer heat from an environmental fluid to the working fluid, and to discharge the working fluid to the distribution manifold.

RELATED APPLICATIONS

This application claims the benefit of and priority to U.S. PatentApplication No. 61/522,247, filed on Aug. 11, 2011, U.S. PatentApplication No. 61/512,379, filed on Jul. 27, 2011, U.S. patentapplication Ser. No. 13/401,618, filed on Feb. 21, 2012, U.S. PatentApplication No. 61/622,982, filed Apr. 11, 2012, U.S. Patent ApplicationNo. 61/622,947, filed Apr. 11, 2012, U.S. patent application Ser. No.12/189,476, filed Aug. 11, 2008, and U.S. Patent Application No.60/954,987, filed Aug. 9, 2007, each of which patent applications ishereby incorporated by reference in its respective entirety, for allpurposes.

BACKGROUND

The innovations and related subject matter disclosed herein(collectively referred to as the “disclosure”) concern systemsconfigured to transfer heat from one fluid to another fluid, and moreparticularly, but not exclusively, to systems having a modularconfiguration. Some systems are described in relation to coolingelectronic components by way of example, though the disclosedinnovations may be used in a variety of other heat-transferapplications.

With the recent explosive growth of cloud-based services, the number ofnetworked computers and computing environments, including servers, assubstantially grown over the past several years. As used herein, theterm “server” generally refers to a computing device connected to acomputing network and running software configured to receive requests(e.g., a request to access or to store a file, a request to providecomputing resources, a request to connect to another client) from clientcomputers also connected to the computing network.

The term “data center” (also sometimes referred to in the art as a“server farm”) loosely refers to a physical location housing one or moreservers. In some instances, a data center can simply comprise anunobtrusive corner in a small office. In other instances, a data centercan comprise several large, warehouse-sized buildings enclosing tens ofthousands of square feet and housing thousands of servers.

Regardless of their size, data centers and the servers they houseconsume vast amounts of electrical power. Although operating serversaccount for a major portion of the power consumed by a given datacenter, cooling the servers using conventional approaches accounts foranother significant portion of the consumed power.

Typical commercially-available servers have been designed to be cooledat least partially by air within the data center. Such servers usuallycomprise one or more printed circuit boards having a plurality ofoperable, heat dissipating devices (e.g., memory, chipsets,microprocessors, hard drives, etc.) mounted thereto. The printed circuitboards are commonly housed in an enclosure having vents configured todirect external air from the data center into, through and out of theenclosure. The air absorbs heat dissipated by the operable components.After exhausting from the enclosure, the heated air mixes with air inthe data center and an air conditioner cools the heated data center air,consuming large amounts of energy in the process.

In general, higher performance server components dissipatecorrespondingly more power. However, the amount of heat thatconventional cooling systems can suitably remove from the variousoperable devices corresponds, in part, to the extent of air conditioningavailable from the data center or other facility, as well as the levelof power dissipated by adjacent components and servers. For example, thetemperature of an air stream entering a server in such a data center canbe influenced by the level of power dissipated by, and proximity of,adjacent servers, as well as the temperature of the air entering thedata center (or, conversely, the rate at which heat is extracted fromthe air within the data center).

In general, a lower air temperature in a data center allows each servercomponent cooled by an air flow to dissipate a higher power, and thusallows each server to operate at a correspondingly higher level ofperformance. Consequently, data centers have traditionally usedsophisticated air conditioning systems (e.g., chillers, vapor-cyclerefrigeration) to cool the air (e.g., to about 65° F.) within the datacenter to achieve a desired degree of cooling (e.g., corresponding to adesired performance level). Some data centers provide chilled watersystems for removing heat from the air within a data center. However,rejecting heat absorbed by air in a data center using sophisticated airconditioning systems, including conventional chilled water systems,consumes high levels of power, and is costly.

In general, heat dissipating components spaced from each other (e.g., alower heat density) can be more easily cooled than the same componentsplaced in close relation to each other (e.g., a higher heat density).Consequently, data centers have also compensated for increased powerdissipation (corresponding to increased server performance) byincreasing spacing between adjacent servers. Nonetheless, relativelylarger spacing between adjacent servers reduces the number of servers in(and thus the computational capacity of) the data center compared torelatively smaller spaces between adjacent servers.

Therefore, there exists a need for an effective and low-cost coolingalternative for cooling electronic components, such as, for example,rack mounted servers within data centers. There also remains a need forlow-profile heat exchange assemblies (e.g., integrated heat sink andpump assemblies) configured to fit within commercially available servershaving a vertical component height of less than 1.75 inches, or less.There also remains a need for heat-transfer systems for cooling varyingnumbers of servers within a given array of servers. In particular, thereremains a need for reliable cooling systems configured to cool a varietyof densities of server components within a rack, with a rack having fromone to 42 servers being but one example of a desirable range of serverdensities to be cooled. There also remains a need for heat transfersystems configured to cool servers within a data center withoutemploying costly air conditioning systems or chilled water systems.

SUMMARY

Innovations disclosed herein overcome many problems in the prior art andaddress the aforementioned, as well as other, needs, and pertaingenerally to modular heat-transfer systems and more particularly, butnot exclusively, to modular components capable of being assembled intosuch systems. For example, some disclosed innovations pertain to coolingsystems configured to cool one or more arrays of independently operableservers. Other innovations relate to configurations of individualmodules capable of being combined with other modules into a modularheat-transfer system. Still other innovations relate to arrangements ofinterconnections between or among such modules. For example, thisdisclosure describes innovative arrays of heat-transfer modulesconfigured to be combined with a manifold module and/or an environmentalcoupler (e.g., a liquid-liquid heat exchange module) to facilitate heattransfer between an environment and one or more operable elements (e.g.,server components). Some disclosed configurations of such modules arecapable of adequately cooling a plurality of rack-mounted servers in adata center without requiring the data center to provide chilled waterat a temperature below an ambient temperature, eliminating the need forcostly and power consuming chillers. And, other innovations relate tomodule and system configurations that eliminate one or more componentsfrom conventional systems while retaining one or more of each eliminatedcomponent's respective functions.

According to a first aspect, innovative modular heat-transfer systemsare disclosed. Some embodiments of such modular systems include an arrayhaving at least one heat-transfer element defining an inlet and anoutlet and being configured to transfer heat to a working fluid from anoperable element corresponding to the at least one heat-transferelement, or to transfer heat from a working fluid to an operable elementcorresponding to the at least one heat-transfer element. A manifoldmodule can have a distribution manifold and a collection manifold. Adecoupleable inlet coupler can correspond to each respective inlet ofeach respective heat-transfer element in the array. Each respectiveinlet coupler can be configured to fluidicly couple the distributionmanifold to the inlet of the respective heat-transfer element. Adecoupleable outlet coupler can correspond to each respective outlet ofeach respective heat-transfer element in the array. Each respectiveoutlet coupler can be configured to fluidicly couple the outlet of therespective heat-transfer element to the collection manifold. Anenvironmental coupler can be configured to receive the working fluidfrom the collection manifold, to transfer heat to an environmental fluidfrom the working fluid or to transfer heat from an environmental fluidto the working fluid, and to discharge the working fluid to thedistribution manifold.

The at least one heat-transfer element in the array can include aplurality of heat-transfer elements. At least one of the heat-transferelements in the array can include a respective plurality of componentheat-exchange modules. The respective plurality of componentheat-exchange modules can be fluidicly coupled with each other inseries. Each of the component heat-exchange modules can include arespective pump configured to urge the working fluid through therespective at least one heat-transfer element.

At least one of the at least one heat-transfer element can include apump configured to urge the working fluid through the respectiveheat-transfer element. The inlet of the respective heat-transfer elementcan be so fluidicly coupleable to the distribution manifold, the outletof the respective heat-transfer element can be so fluidicly coupleableto the collection manifold, and the environmental coupler can be sofluidicly coupleable to the distribution manifold and to the collectionmanifold as to be capable of defining a closed-loop fluid circuit. Thepump can be so configured as to be capable of urging the working fluidthrough the closed-loop fluid circuit.

The environmental coupler can include a liquid-liquid heat exchangerconfigured to transfer heat to or from a liquid-phase of theenvironmental fluid.

The decoupleable fluid coupler of the inlet conduit can be so configuredas not to be matingly engageable with any of the collection fluidcouplers of the manifold module. The decoupleable fluid coupler of theoutlet conduit can be so configured as not to be matingly engageablewith any of the distribution fluid couplers defined by the manifoldmodule.

The at least one heat-transfer element can include a corresponding pairof component heat-exchange modules. Each in the pair of componentheat-exchange modules can be configured to transfer heat dissipated by arespective electrical, opto-electrical or optical device to the workingfluid. In some embodiments of innovative modular heat-transfer systems,a working fluid reservoir can be fluidicly coupled to the manifoldmodule.

Some innovative modular heat-transfer systems also include a rackconfigured to receive at least one independently operable server. Eachin the at least one independently operable server can include anoperable element. The rack can be configured to mountably receive themanifold module. One heat-transfer element can correspond to each atleast one independently operable server and can be configured totransfer heat dissipated by the respective independently operable serverto the working fluid. The environmental coupler can be configured toreject at least a portion of the heat dissipated by the respectiveindependently operable server heat to the environmental fluid from theworking fluid.

Some innovative modular heat-transfer systems include a sensorconfigured to emit a signal corresponding to one or more of a relativehumidity of an environment, an absolute humidity of an environment, atemperature of an environment, a wet-bulb temperature of an environment,a temperature of the working fluid in a portion of the manifold module,a temperature of the working fluid in a portion of the environmentalcoupler, a temperature of the environmental fluid in a portion of theenvironmental coupler, a volume of the working fluid in a portion of theenvironmental coupler, a temperature of the working fluid in a portionof one or more heat-transfer elements, a leak of the working fluid, aleak of the environmental fluid, or a combination thereof. Someinnovative modular heat-transfer systems include one or more actuatablevalves configured to limit a flow of the working fluid, theenvironmental fluid, or both, at least partially responsively to thesignal emitted by the sensor.

A supply apparatus can be configured to supply to the environmentalcoupler the environmental fluid at a relatively lower temperaturecompared to a temperature of the working fluid within the environmentalcoupler. A heat exchanger can be configured reject, from theenvironmental fluid to an environment, heat absorbed by theenvironmental fluid from the working fluid within the environmentalcoupler. The supply apparatus can include an air-cooled environmentalheat exchanger configured to reject heat from the environmental fluid toatmospheric air.

According to a second aspect, innovative coolant heat-exchange modulesare disclosed.

In some embodiments, a coolant heat-exchange module includes an inletconfigured to receive a working fluid from a collection manifold, and anoutlet configured to discharge the working fluid to a distributionmanifold. A heat exchanger can be configured to reject to a relativelycooler environmental fluid, from the working fluid, heat absorbed by theworking fluid from an array of operable elements.

In some embodiments, the coolant heat-exchange module can be mountablycoupleable to an equipment enclosure housing the array of operableelements. The heat exchanger can be so configured as to provide asufficient rate of heat transfer from the working fluid to cool theworking fluid to a suitable temperature when the working fluid isconveyed by one or more pumps positioned externally of the coolant heatexchange module.

The one or more pumps positioned externally of the coolant heat exchangemodule can include a pump fluidicly coupled between the collectionmanifold and the distribution manifold. For example, a plurality ofpumps fluidicly can be coupled between the collection manifold and thedistribution manifold.

In some instances, but not all, the coolant heat-exchange module furthercan include a pump. Such a pump can be fluidicly coupled between theinlet and the heat exchanger, such a pump can be fluidicly coupledbetween the heat exchanger and the outlet, or both.

In some instances, one or more actuatable valves are configured tocontrol a flow rate of the environmental fluid, the working fluid, orboth. A temperature sensor can be configured to measure a temperature ofa surface of the coolant heat-exchange module, an ambient airtemperature, or both. A humidity sensor can be configured to measure ahumidity of ambient air in which the coolant heat-exchange module isinstalled.

Some coolant heat-exchange modules also include a calculator configuredto determine a dew point temperature at least partially based on thehumidity of ambient air measured by the humidity sensor. A controllercan be configured to actuate at least one of the one or more actuatablevalves at least partially responsively to the dew point temperaturedetermined by the calculator.

Some coolant heat-exchange modules include one or more sensors, eachsensor being configured to emit a signal corresponding to one or more ofa relative humidity of an environmental fluid, an absolute humidity ofan environmental fluid, a temperature of an environmental fluid, atemperature of a liquid in the manifold module, a temperature of aliquid in the first fluid conduit of the heat exchanger, a temperatureof a liquid in the second fluid conduit of the heat exchanger, a volumeof coolant in the coolant reservoir, a temperature of a liquid in one ormore of the plurality of equipment heat exchangers, a temperature of asurface of one or more of the plurality of equipment heat exchangers, atemperature of the facility coolant entering the second fluid conduit, atemperature of the facility coolant flowing from the second fluidconduit, a leak of equipment coolant, a leak of facility coolant, or acombination thereof. The controller can also be configured to actuatethe one or more actuatable valves to control a flow rate of theenvironmental fluid, the working fluid, or both, at least partiallyresponsively to a signal received from one of the one or more sensors.

Some coolant heat-exchange modules include a transmitter configured totransmit a signal containing information corresponding to the signalreceived from the one or more sensors.

The controller and the calculator can together be configured to preventcondensation from forming on the coolant heat exchange module or anyfeature thereof.

According to a third innovative aspect, heat-exchange elements aredisclosed. A heat-exchange element can include a first heat sink havinga first plurality of juxtaposed fins defining a corresponding firstplurality of microchannels between adjacent fins. Each of the fins candefine a respective distal edge. A first manifold body can overlie atleast a portion of each of the distal edges of the first heat sink anddefine an opening configured to deliver a flow of fluid to themicrochannels of the first heat sink in a direction transverse to themicrochannels of the first heat sink.

A second heat sink can have a second plurality of juxtaposed finsdefining a corresponding second plurality of microchannels betweenadjacent fins. Each of the fins can define a respective distal edge. Asecond manifold body can overlie at least a portion of each of thedistal edges of the second heat sink and define an opening configured todeliver a flow of fluid to the microchannels of the second heat sink ina direction transverse to the microchannels of the second heat sink.

The second manifold body and the second heat sink can be fluidiclycoupled with the first heat sink in series.

Other innovative aspects of this disclosure will become readily apparentto those having ordinary skill in the art from a careful review of thefollowing detailed description (and accompanying drawings), whereinvarious embodiments of disclosed innovations are shown and described byway of illustration. As will be realized, other and differentembodiments of modules and systems incorporating the disclosedinnovations are possible and several disclosed details are capable ofbeing modified in various respects, all without departing from thespirit and scope of the principles disclosed herein. For example, thedetailed description set forth below in connection with the appendeddrawings is intended to describe various embodiments of the disclosedinnovations and is not intended to represent the only embodimentscontemplated by the inventor. Instead, the detailed description includesspecific details for the purpose of providing a comprehensiveunderstanding of the principles disclosed herein. Accordingly thedrawings and detailed description are to be regarded as illustrative innature and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

Unless specified otherwise, the accompanying drawings illustrate aspectsof the innovative subject matter described herein. Referring to thedrawings, wherein like reference numerals indicate similar partsthroughout the several views, several examples of systems incorporatingaspects of the presently disclosed principles are illustrated by way ofexample, and not by way of limitation, wherein:

FIG. 1 shows an isometric view of one embodiment of a modularheat-transfer system configured to cool a plurality of independentlyoperable, rack-mounted servers;

FIG. 2 shows an isometric view of a portion of the modular heat-transfersystem shown in FIG. 1, together with features of a heat-transferelement;

FIG. 3 shows a schematic illustration of a modular heat-transfer system;

FIG. 4 shows a schematic illustration of a portion of the modularheat-transfer system shown in FIG. 3;

FIG. 5 shows a schematic illustration of the modular heat-transfersystem shown in FIGS. 1 and 2, with features of the heat-transferelements and several corresponding fluid couplers shown;

FIG. 6 shows a schematic illustration of the modular heat-transfersystem in FIG. 5 with features of the heat-transfer elements and theenvironmental coupler shown;

FIG. 6A shows a schematic illustration of an alternative configurationof a heat-transfer element;

FIG. 6B shows a schematic illustration of an alternative configurationof a coolant heat exchanger.

FIG. 7 shows a schematic illustration of a manifold module of the typeshown in FIGS. 1 and 3;

FIG. 8 shows an isometric view of a portion of the modular heat-transfersystem shown in FIG. 1, with features of the environmental couplershown;

FIG. 9 shows a block diagram of a controller suitable for controlling amodular heat-transfer system of the type shown in FIG. 1;

FIG. 10 shows a block diagram of a computing environment suitable foruse in combination with a controller as shown in FIG. 9.

FIG. 11 illustrates an exploded view of one embodiment of an integratedpump and heat exchanger assembly.

DETAILED DESCRIPTION

The following describes various innovative principles related to moduleheat-transfer systems by way of reference to specific examples ofmodular heat-transfer systems, and more particularly but notexclusively, to modular heat-transfer systems configured to cool anarray of servers (e.g., in a data center). Nonetheless, one or more ofthe disclosed principles can be incorporated in various systemconfigurations to achieve any of a variety of corresponding systemcharacteristics. Systems described in relation to particularconfigurations, applications, or uses, are merely examples of systemsincorporating one or more of the innovative principles disclosed hereinand are used to illustrate one or more innovative aspects of thedisclosed principles.

Thus, heat-transfer systems having attributes that are different fromthose specific examples discussed herein can embody one or more of theinnovative principles, and can be used in applications not describedherein in detail, for example, to transfer heat to or from lasercomponents, light-emitting diodes, chemical reactants undergoing achemical reaction, photovoltaic cells, solar collectors, powerelectronic components, electronic components other than microprocessors,photonic integrated circuits, and other electronic modules, as well as avariety of other industrial, military and consumer devices now known orhereafter developed. Accordingly, such alternative embodiments also fallwithin the scope of this disclosure.

Overview

Following is a description of modular heat-transfer systems configuredto transport heat between an array of heat-transfer elements and anenvironmental heat-transfer coupler. Some disclosed modularheat-transfer systems are configured to cool an array of n independentlyoperable servers (or components thereof). Other disclosed modularheat-transfer systems are configured, for example, to heat a solution ofchemical reactants undergoing an endothermic chemical reaction.

Server Cooling Systems

As but one example of disclosed heat-transfer systems, FIG. 1 shows acooling system configured to cool an array of independently operableservers 112 a, 112 b. . . 112 n mounted in a rack, or chassis. Forexample, each in an array of heat-transfer elements 110 a, 110 b. . .110 n can be thermally coupled to a respective component that dissipatesheat during operation of the servers 112 a, 112 b. . . 112 n.

A manifold module 200 can be configured to distribute a relativelycooler coolant among the plurality of heat-transfer elements 110 a, 110b. . . 110 n, allowing the coolant to absorb heat from the servers andto cool the respective components within the servers. The manifold 200can collect the working fluid from the array of heat-transfer elementsand convey the working fluid to an environmental coupler 15 (e.g., aliquid-liquid heat exchanger).

FIG. 2 shows a representative heat-transfer element 110 a within arepresentative one of the servers (e.g., server 112 a). Therepresentative heat-transfer element 110 a can have a modularconfiguration (e.g., including a pair of component heat-transfer modules120 a, 130 a configured to cool a corresponding pair of microprocessorsor other server components (not shown)). An inlet to the heat-transferelement 110 a can be fluidicly coupled to a distribution manifold 210and an outlet of the heat-transfer element 110 a can be fluidiclycoupled to a collection manifold 220.

The environmental coupler 15 can be configured to facilitate therejection of heat from the coolant to an environmental working fluid(e.g., facility water) to cool the coolant. For example, theenvironmental coupler 15 can be cooled by passing a relatively coolerenvironmental working fluid from the environment 16 through the coupler15. As the relatively warm coolant (or, more generally, working fluid)passes through the environmental coupler 15, it rejects at least some ofthe heat absorbed in the heat-transfer elements to the environment 16(e.g., the environmental working fluid), cooling the working fluid.Afterward, the relatively cooler coolant can be re-distributed among theheat-transfer elements by the manifold module, providing substantiallycontinuous cooling to the array of servers.

As but one example, discussed more fully below and shown in FIG. 1, anequipment heat-transfer module 100 can include a chassis 101, or rack,configured to receive a plurality of independently operable servers. Themanifold module 200 can be positioned adjacent the chassis 101, and thechassis can support the environmental coupler.

Other Modular Heat-Transfer Systems

Other modular heat-transfer system configurations are also describedherein. As indicated in FIGS. 3 and 4, a modular heat transfer system10′ can be generalized from the system shown in FIGS. 1 and 2.

For example, such a system 10′ can have a manifold 200′ configured todistribute a working fluid among an array 100′ of n heat-transferelements 110 a′, 110 b′ . . . 110 n′, each being thermally coupled to arespective operable element (not shown) within a corresponding array ofn operable elements. As with the modular heat-transfer system 10 shownin FIG. 1, the modular heat-transfer system 10′ shown in FIG. 3 can havean equipment heat-transfer module 12′ configured to exchange heatbetween an array 100′ of one or more heat-transfer elements 110 a′, 110b′, . . . 110 n′ and a coolant heat-exchange module 300′ having anenvironmental coupler 15′ (e.g., a liquid-liquid heat exchanger) bycirculating a working fluid through a fluid circuit 17 a, 17 b, 17 c, 17d. The coupler 15′ can be configured to transfer heat 111 (e.g., 111 a,111 b. . . 111 n in FIG. 3) between the equipment heat-transfer module12′ and an environmental working fluid 40′ (e.g., a facility's watersupply) in an environment 16′. In a general sense, the modularheat-transfer system 10′ can be configured to reject heat to theenvironment 16′ (as in server-cooling applications) or to absorb heatfrom the environment (as in applications pertaining to endothermicreactions).

Apart from systems configured to cool a plurality of servers thatdissipate heat during operation, some disclosed heat transfer systemscan be configured to heat a plurality of devices. As but one example, achemical processor can be configured to house a plurality of endothermicchemical reactions. An array of heat-transfer elements can be configuredto transfer heat to the chemical processor from an environment 16′. Forexample, the environmental coupler 15′ can be maintained at a relativelywarmer temperature, and heat can be transferred from the coupler to anarray 100′of relatively cooler heat-transfer elements. In such aninstance, the working fluid within the equipment heat-transfer module12′ can circulate as described above, carrying heat from the relativelyhigher temperature coupler 15′, through a manifold module 200, andrejecting heat to one or more relatively cooler operable elements (e.g.,reactor vessels) corresponding to a respective one or more heat-transferelements 110 a′, 110 b′ . . . 110 n′ in the array 100′.

The array of n operable elements (e.g., reactor vessels) can be coupledto a chassis, an enclosure or other housing, and the chassis, enclosureor other housing can form a portion of the heat-transfer module 12′.

Heat-transfer systems configured as shown in FIGS. 1 and 3 can providescalable rates of heat transfer for arrays having varying numbers ofindependently operable elements at relatively low overall cost, amongmany advantages, compared to conventional heat-transfer systems.

Working Fluids

As used herein, “working fluid” means a fluid used for or capable ofabsorbing heat from a region having a relatively higher temperature,carrying the absorbed heat (as by advection) from the region having arelatively higher temperature to a region having a relatively lowertemperature, and rejecting at least a portion of the absorbed heat tothe region having a relatively lower temperature.

In some embodiments (e.g., endothermic chemical reactions), theenvironmental working fluid has a relatively higher temperature than anoperable component (e.g., a reaction chamber) corresponding to a givenheat-transfer element in the array 100′ (FIG. 4). In other embodiments(e.g., exothermic chemical reactions, servers, lasers), theenvironmental working fluid has a relatively lower temperature than anoperable component (e.g., a reaction chamber, an integrated circuit, alight source).

As used herein, “coolant” refers to a working fluid capable of beingused in or actually being used in a heat-transfer system configured tomaintain a region of a device at or below a selected thresholdtemperature by absorbing heat from the region. Although manyformulations of working fluids are possible, common formulations includedistilled water, ethylene glycol, propylene glycol, and mixturesthereof.

Equipment Module

Many varieties of apparatus can be configured to receive a plurality ofoperable elements. For example, an equipment enclosure, commonlyreferred to as an “equipment rack” or a “rack”, can be configured toreceive a plurality of independently operable equipment elements (e.g.,servers), as shown in FIG. 1.

Although a cooling system for a rack-mounted server is described in somedetail as an example of a modular heat-transfer system incorporatingdisclosed principles, other embodiments of heat-transfer systems arecontemplated. For example, scientific instruments, telecommunicationsdevices (e.g., routers and switches), audio equipment (e.g., amplifiers,pre-amplifier conditioning units, and audio receivers), video equipment(e.g., players), laser equipment, lighting equipment (e.g., incandescentlighting and light-emitting diodes), chemical processing equipment,biological processing equipment and other equipment, are contemplatedembodiments of operable elements to which modular heat-transfer systemscan be applied. Such operable elements can be received by an equipmentenclosure, and such an equipment enclosure can be included in anequipment module 12.

Some commercially available equipment racks are configured to receiveoperable elements having a frontal area measuring about 19-inches wideand an integer-multiple of about 1.75 inches in height. An operableelement's height is sometimes measured in Rack Units (commonly referredto as “U” or, less commonly, “RU”). Thus, an operable element measuringabout 1.75 inches in height measures 1U in height, and is sometimesreferred to as a “1U” element. Similarly, a 2U element measures about3.5 inches in height, and a 4U element measures about 7 inches inheight.

To facilitate installation in commonly available racks, most operableelements 112 a, 112 b . . . 112 n have a front-panel height measuringabout 1/32-inches (0.31 inches) less than the corresponding multiple ofrack units. For example, a 1U element typically measures about 1.719inches tall, rather than 1.75 inches tall, and a 2U typically measuresabout 3.469 inches tall instead of 3.5 inches tall. A gap above and/orbelow an installed piece of equipment facilitates installation andremoval without mechanically interfering with adjacent equipment.

Other standardized equipment racks are also commercially available. Inthe telecommunications industry, for example, equipment racks commonlyare configured to receive operable elements having a frontal areameasuring about 23 inches wide and about 1 inch in height.

Although standardized equipment enclosures are described in some detailherein, other embodiments of equipment modules are contemplated. Forexample, an equipment module need not be distinct from an operableelement or configured to receive an operable element to take advantageof the scalable nature of disclosed heat-transfer systems. For example,an enclosure of a mainframe- or a super-computer can include a coolantheat exchanger, manifold module and an array of heat-transfer elementsas disclosed herein. In other embodiments, an equipment module can beconfigured as a room or a closet within a structure, or a volume withinan airframe selected to house a plurality of operable elements.

Heat-Transfer Elements

As noted above, an array of one or more heat-transfer elements 110 a,110 b. . . 110 n can be configured to transfer heat to or from a workingfluid passing through the respective heat-transfer elements. As shown,for example, in FIGS. 2 and 7, each heat-transfer element 110 a, 110 b.. . 110 n can include one or more heat exchange modules (120 a, 120 b)configured to absorb heat from, or to reject heat to, an operableelement or a component thereof.

As used herein, the terms “heat sink” and “heat exchanger” areinterchangeable and mean a device configured to transfer energy to orfrom a fluid, as through convection (i.e., a combination of conductionand advection) or phase change of a working fluid. A heat exchangemodule can be a heat exchanger, or can include a heat exchanger incombination with one or more other components. For example, as describedmore fully below, a heat exchange module can include a duct or a housingin combination with a heat exchanger. As well, a heat exchange modulecan include a heat exchanger in combination with an integrated housingand a pump, together with any associated seals, gaskets and/or couplers.

Several examples of suitable heat exchange modules are described, forexample, in U.S. Patent Application No. 60/954,987, filed on Aug. 9,2007, U.S. patent application Ser. No. 12/189,476, filed on Aug. 11,2008, U.S. Patent Application No. 61/512,379, filed on Jul. 27, 2011,U.S. patent application Ser. No. 13/401,618, filed on Feb. 21, 2012, andU.S. Patent Application No. 61/622,982, filed on Apr. 11, 2012, whichpatent applications are hereby incorporated by reference in theirentirety, for all purposes.

As noted, some heat-transfer elements 110 a, 110 b. . . 110 n include aplurality of heat exchange modules 120 a, 130 a, 120 b, 130 b. . . 120n, 130 n (FIG. 6). Each in the plurality of heat exchange modules cancorrespond to, for example, a respective heat-dissipating device, or agroup of respective heat dissipating devices, within a given operableelement (e.g., server).

Plural heat exchange modules, e.g., modules 120 a, 130 a, can befluidicly coupled to each other in series (e.g., such that a volume ofworking fluid passes from one heat exchange module 120 a to another heatexchange module 130 a before returning to a collection manifold 210 (orother system component), as shown for example in FIGS. 2 and 7).Alternatively, plural heat exchange modules, e.g., modules 120 a″, 130a″, can be fluidicly coupled to each other in parallel within a givenheat-transfer element 110 a″ (e.g., such that a first mass of workingfluid passes through one heat exchanger 120 a″ and a second mass ofworking fluid passes through another heat exchanger 130 a″), as shown inFIG. 6A.

In the context of a rack-mountable server having a plurality ofheat-dissipating devices (e.g., microprocessors, chipsets, memory,graphics components, voltage regulators), a heat-transfer element 110 a,110 b. . . 110 n can include a single-phase or a two-phase heat exchangemodule for cooling the respective devices. As used herein, “phase”refers to a thermodynamic state of a substance, e.g., a liquid phase, agas phase, a solid phase, or a saturated mixture of liquid and gas. Asused herein, a “single-phase” heat exchange module refers to a heatexchange module in which the working fluid undergoes little or no netchange of phase, remaining in substantially the same phase (e.g., aliquid) as the fluid passes through the heat exchange module. As usedherein, a “two-phase” heat exchange module refers to a heat exchangemodule in which the working fluid undergoes a change of phase (e.g.,evaporation of a liquid to a gas phase or condensation of a gas to aliquid phase) as the fluid passes through the heat exchange module.

For a given mass of working fluid, a “two-phase” heat exchange modulecan typically absorb or reject more heat for a given change intemperature, and in some instances provide more suitable cooling orheating relative to a given temperature threshold, than a “single-phase”heat exchange module because the latent heat of vaporization (orcondensation) of most working fluids is substantially greater than thespecific heat of the fluid (e.g., a single-phase fluid may changetemperature in proportion to the amount of absorbed or rejected heat,whereas a fluid undergoing phase-transition typically stays within arelatively narrower range of temperature as it absorbs or rejects heat).

Since a temperature and/or a phase of a given mass of working fluid canchange as it passes through a first heat exchange module, the capacityof the given mass of working fluid to exchange heat as it passes througha second heat exchange module fluidicly coupled to the first heatexchanger in series may be somewhat diminished as compared to the casein which a comparable mass of working fluid enters the second heatexchange module without being heated by the first heat exchange module(e.g., assuming a temperature of the fluid and/or the downstream heatexchanger is limited by a fixed upper threshold temperature).Nonetheless, in many instances, including many equipment coolingembodiments (e.g., cooling rack-mountable servers shown in FIG. 1), sucha temperature change does not appreciably diminish the cooling capacityof a downstream heat exchanger. For example, a flow rate of the workingfluid can be increased to compensate for relatively higher rates of heatdissipation by an operable element, ensuring that a temperature of aworking fluid within the respective heat-transfer element 110 a, 110 b.. . 110 n remains below an upper threshold temperature before entering adownstream heat exchanger. Similarly, for relatively lower rates of heatdissipation, a flow rate of the working fluid can be decreased to asuitable level that maintains a given temperature below an upperthreshold while simultaneously reducing the amount of power consumed topump the fluid through the heat-transfer element (and/or through thesystem 10).

Component Heat-Exchange Modules

A variety of heat exchange module and pump embodiments are suitable tobe incorporated into a heat-transfer element 110 a, 110 b. . . 110 n ofthe type described above. For example, several representativeembodiments of heat exchange modules and pump configurations aredisclosed in U.S. Patent Application No. 60/954,987, filed on Aug. 9,2007, U.S. patent application Ser. No. 12/189,476, filed on Aug. 11,2008, U.S. Patent Application No. 61/512,379, filed on Jul. 27, 2011,U.S. patent application Ser. No. 13/401,618, filed on Feb. 21, 2012, andU.S. Patent Application No. 61/622,982, filed Apr. 11, 2012, whichpatent applications are hereby incorporated by reference in theirentirety, for all purposes, and each of which is incorporated herein inits entirety by reference and owned by the Assignee of this application.

As but one example, the '379 Application discloses embodiments of a heatexchange module having an integrated pump fluidicly coupled to a heatexchanger in series and positioned upstream of the heat exchanger. Asthe '379 Application explains, a working fluid can enter an inlet to aheat exchange module and the pump can increase a pressure head in theworking fluid, urging the working fluid through the corresponding heatexchanger. The '379 Application also discloses that, in someembodiments, after passing through the respective heat exchanger, theworking fluid exhausts from the heat exchange module and passes througha remotely positioned heat exchanger (e.g., to reject heat absorbedpassing through the respective heat exchanger).

Referring now to FIG. 11, a working example of an integrated subassemblyis described.

The illustrated subassembly 1300 comprises a pump 1310 and a heatexchanger 1320, as well as housing 1330 with integrated fluid conduitsextending therebetween. The subassembly 1300 is but one example of anapproach for integrating several elements of the fluid circuit (e.g.,the pump and the first heat exchanger, including the inlet manifold, thefluid passages, the exhaust manifold) into a single element whileretaining the several elements' respective functions. The housing 1330is configured to convey a working fluid from an inlet port 1331 to apump volute 1311, from the pump volute to an inlet 1321 to the heatexchanger 1320, and from an outlet 1322 of the heat exchanger to anoutlet port 1332.

The pump impeller 1312 can be received in the pump volute 1311. Theimpeller can be driven in rotation by an electric motor 1313 in aconventional manner. A cap 1301 can overlie the motor 1313 and fasten tothe housing 1330 to provide the subassembly 1300 with a finishedappearance suitable for use with, for example, consumer electronics.

The side 1333 of the housing 1330 positioned opposite the pump volute1311 can receive an insert 1334 and the heat exchanger 1320. A seal(e.g., an O-ring) 1323 can be positioned between the housing 1330 andthe heat exchanger 1320 to reduce and/or eliminate leakage of theworking fluid from the interface between the heat exchanger 1320 and thehousing 1330.

The heat exchanger 1320 defines a lower-most face of the assembly 1300,as well as a surface configured to thermally couple to an integratedcircuit (IC) package (not shown). A retention mechanism 1302 canmechanically couple the assembly to a substrate, such as a printedcircuit board to which the IC package is assembled.

A plurality of heat exchange modules of the type disclosed in the '379Application, as well as in other above referenced patent applications,can be fluidicly coupled to each other in series or in parallel, andused to exchange heat with one or more corresponding components. As butone example, FIGS. 2 and 6 illustrate two heat exchange modules, e.g.,modules 120 a, 130 a, fluidicly coupled to each other in series. FIG.6A, on the other hand, shows two heat exchange modules, e.g., modules120 a″, 130 a″, fluidicly coupled to each other in parallel.

When two heat exchange modules 120 a, 130 a are coupled to each other inseries, the working fluid can pass from one heat exchange module 120 ainto the other heat exchange module 130 a (e.g., before flowing througha remotely positioned heat exchanger). For example, an inlet 121 to afirst heat exchange module 120 a having a pump and a heat exchanger canbe fluidicly coupled to a distribution manifold 210. An outlet 122 fromthe first heat exchange module 120 a can be fluidicly coupled to aninlet 131 to a second heat exchange module 130 a having a pump and aheat exchanger. An outlet 122 from the second heat exchange module 130 acan be fluidicly coupled to a collection manifold 220.

In such a series configuration, a working fluid exhausts from thedistribution manifold 210 and enters the inlet 121 to the first (e.g.,the upstream) heat exchange module 120 a. The working fluid then entersinto the corresponding pump volute defined by the integrated housing,allowing the pump impeller to increase a pressure head in the workingfluid. The fluid subsequently passes from the heat exchanger, andexhausts from the outlet 122 of the first heat exchange module 120 a.

With the first and the second heat exchange modules 120 a, 130 afluidicly coupled to each other in series, the fluid then enters theinlet 131 to the second (e.g., downstream) heat exchange module 130 a.In the second heat exchange module 130 a, the working fluid follows asimilar path as through the first heat exchange module 120 a, e.g.,flows through a pump and downstream heat exchanger before exhaustingfrom the outlet 132 of the second heat exchange module 130 a, and flowsinto the collection manifold 220.

Fluidicly coupling heat exchange modules to each other in series, asdescribed above, can provide a measure of redundancy to the fluiddistribution system. For example, coupling a plurality of heat exchangemodules, e.g., modules 120 a, 130 a, each having a corresponding pumpand a corresponding heat exchanger, fluidicly couples a correspondingplurality of pumps to each other in series. Accordingly, should one ofthe plurality of pumps fail (e.g., become inoperable or insufficientlyoperable), the remaining pump(s) can cause the working fluid to continueflowing through the respective heat exchange element.

When coupled to each other in series, a heat exchange module positioneddownstream of another heat exchange module will typically receive arelatively higher-temperature working fluid (e.g., working fluid thatabsorbed heat as it passed through the upstream heat exchange module) ascompared to heat exchange modules fluidicly coupled to each other inparallel. Nonetheless, since the mixed mean temperature of the workingfluid as it exhausts from the upstream heat exchange module corresponds,at least in part, to the mean flow rate of the working fluid through theupstream heat exchange module, a suitable flow rate of the working fluidcan be selected to maintain a temperature of the working fluid below apredetermined threshold temperature. As an example, the thresholdtemperature can correspond, at least in part, to a rate of coolingprovided by the downstream heat exchange module.

When two heat exchange modules 120 a″, 130 a″ are coupled to each otherin parallel, e.g., as shown in FIG. 6A, the working fluid can pass fromeach heat exchange module 120 a″, 130 a″ into the collection manifold220 without passing through the other heat exchange module. For example,an inlet to each heat exchange module 120 a″, 130 a″ can be fluidiclycoupled to the distribution manifold 210, and a corresponding stream ofworking fluid can pass through each of the heat exchange modules. Therespective streams can mix with each other in a manifold (e.g., thecollection manifold). Although coupling heat exchange modules to eachother in parallel does not provide redundant pumping (as series couplingprovides), each respective stream of working fluid can pass through theparallel heat exchange modules without being heated by other of the heatexchange modules coupled in parallel.

Fluid Distribution

Many liquid-phase working fluids are substantially incompressibleliquids. Accordingly, one or more pumps configured to increase apressure head in the working fluid, and thereby to urge the workingfluid through the fluid circuit extending between and passing throughthe environmental coupler 15 and the equipment module 100, can bepositioned in any suitable or convenient location within the circuit, asdescribed more fully below.

A given heat-transfer element 110 a, 110 b. . . 110 n can include one ormore pumps configured to increase a pressure head of the working fluidas the working fluid passes through the heat-transfer element. The pumpscan be fluidicly coupled to each other in series or in parallel.

Compared to a single pump, pumps coupled to each other in series tend toprovide a relatively larger increase in pressure head at about the sameflow rate, as measured between an inlet to an upstream pump and anoutlet of a downstream pump. Compared to a single pump, pumps coupled toeach other in parallel tend to provide a relatively larger flow rate,cumulatively, at about the same increase in pressure head.

Some heat-transfer elements have one pump and a plurality of heatexchange modules. As explained above in relation to FIG. 6 and FIG. 6A,the plurality of heat exchanger modules can be fluidicly coupled to eachother in series or in parallel. The plurality of heat exchange modulescan be fluidicly coupled to the pump in series (e.g., positionedupstream or downstream of the pump).

Other heat-transfer elements have a plurality of pumps and a pluralityof heat exchangers fluidicly coupled to each other. The plurality ofpumps can be fluidicly coupled to each other in parallel or in series,and the heat exchange modules can be fluidicly coupled to each other inparallel or in series. One or more in the plurality of heat exchangerscan be fluidicly coupled in parallel or in series with one or more ofthe plurality of pumps.

For example, a first plurality of heat exchange modules can be fluidiclycoupled to each other in parallel or in series. The first plurality ofheat exchange modules can be fluidicly coupled to a corresponding firstplurality of pumps in series (e.g., positioned upstream or downstream ofthe pumps). The first plurality of pumps can be fluidicly coupled toeach other in parallel or in series. A second plurality of heat exchangemodules can be fluidicly coupled to each other in parallel or in series.The second plurality of heat exchangers can be fluidicly coupled to asecond plurality of pumps in series (e.g., positioned upstream ordownstream of the pumps). The respective first and second pluralities ofpumps can be fluidicly coupled to each other in parallel or in series.

Plural heat-transfer elements 110 a, 110 b. . . 110 n corresponding to agiven equipment module 100 can be fluidicly coupled to each other inseries or in parallel. By way of example, FIGS. 1, 2, 3, 5 and 6 showrepresentative embodiments of a plurality of heat-transfer elements 110a, 110 b. . . 110 n fluidicly coupled with each other in parallel. Asexplained above, each of the heat-transfer elements, in turn, can have aplurality of heat exchange modules fluidicly coupled to each other inseries (or in parallel).

As FIG. 6 shows, the respective inlets 150 a, 150 b. . . 150 n to eachof the heat-transfer elements 110 a, 110 b. . . 110 n can be fluidiclycoupled to the distribution manifold 210, and the respective outlets 140a, 140 b. . . 140 n of each of the heat-transfer elements can befluidicly coupled to the collection manifold 220. With such a parallelconfiguration of heat-transfer elements 110 a, 110 b. . . 110 n, a givenmass of working fluid can pass through one heat-transfer element withoutpassing through another heat-transfer element.

Such a parallel configuration reduces thermal coupling among the servers112 a, 112 b. . . 112 n by preventing a given mass of working fluid thathas passed through one heat transfer element from passing throughanother heat transfer element until absorbed heat can be rejected fromthe working fluid (e.g., in the coolant heat exchange module). As well,such a configuration allows the pump(s) in the plural heat-transferelements 110 a, 110 b. . . 110 n to urge the working fluid throughoutthe equipment heat exchange module 12, which can eliminate or reduce theneed for pumps apart from those within the heat-transfer elements.

Nonetheless, some embodiments of disclosed heat exchange systems includea “system” pump positioned within the fluid distribution circuit andspaced from the component heat exchange modules, e.g., modules 120 a,130 a. For example, a pump can be positioned in series between themanifold module 200 and the environmental coupler 15 (e.g., in the fluidheat exchange module 300). As but one example, the coolant heat exchangemodule shown in FIG. 6B includes a pump 317 positioned downstream of thereservoir 315 (although, the pump can be positioned upstream of thereservoir in other embodiments).

Even so, fluidicly coupling the heat-transfer elements in parallel witheach other provides a measure of redundancy that otherwise would beunavailable if a pump was positioned in, for example, the working fluidheat exchange module 300. For example, if a given heat-transfer elementfails or otherwise degrades in performance, the degraded heat-transferelement and any associated operable elements (e.g., a server) can beremoved from the equipment heat exchange module 100 (and the associatedrack) without affecting the operation of any remaining heat-transferelements or operable elements.

As well, if one of the pumps in a given heat-transfer element fails, theother pump(s) in the heat-transfer element can continue to urge theworking fluid through the heat-transfer element (e.g., through therespective heat exchange modules), allowing the working fluid tocontinue to exchange heat with each operable element in thermal contactwith a respective component heat exchange module until the heat-transferelement 110 a can be repaired or replaced.

Additionally, fluidicly coupling the heat exchange modules in a givenheat-transfer element, e.g., 110 a, with each other in series allows theflow-rate through the respective heat-transfer element to be selected tocorrespond with a desired rate of heat transfer through the heatexchange modules. For example, if a heat exchanger is thermally coupledwith a heat dissipating device and a relatively higher rate of heattransfer from the device into the working fluid is desired, a relativelyhigher flow rate of the working fluid can be provided by, for example,increasing the speed of one or more of the respective pumps in the givenheat-transfer element 110 a.

Heat-transfer elements having independently controllable pumps and beingfluidicly coupled to each other in parallel also allows a flow ratethrough each respective heat-transfer element 110 a, 110 b. . . 110 n tobe controlled independently of the other heat-transfer elements. Suchindependent control of working-fluid flow rates through each respectiveheat-transfer element 110 a, 110 b. . . 110 n allows the power consumedby the respective working elements to be selected to correspond to adesired rate of heat transfer to or from each respective heat-transferelement. For example, selecting a suitably low power for each respectiveheat-transfer element in the plurality of heat-transfer elements 110 a,110 b. . . 110 n can provide a relatively lower overall powerconsumption for the equipment module 100 than if each heat-transferelement had an identical flow rate to the other heat-transfer elements(e.g., corresponding to the highest rate of heat transfer for anoperable element in an array of operable elements), particularly whenthe desired rates of heat transfer to or from each heat-transfer elementvaries substantially among the plurality of heat-transfer elements.

Fluid Couplers

As used herein, “fluidic” means of or pertaining to a fluid (e.g., agas, a liquid, a mixture of a liquid phase and a gas phase, etc.). Thus,two regions that are “fluidicly coupled” are so coupled to each other asto permit a fluid to flow from one of the regions to the other region inresponse to a pressure gradient between the regions.

As indicated in FIG. 5, one or more of the fluid conduits 20, 30, 40that fluidicly couple one module to another module (e.g., the equipmentmodule 100 to the manifold module 200, or the manifold module to thecoolant heat-exchange module 300) can be coupled to one or both of therespective modules by a decoupleable coupler (e.g., couplers 50, 50 a,50 b, 51 a, 52 a, 52 b, 55 a, 55 b). Some decouplable couplers areconfigured as dripless quick-connect couplers of the type commerciallyavailable from Colder Products Company.

As FIG. 6 indicates, the fluid conduit 162 a, 162 b. . . 162 n extendingfrom the respective inlets 150 a, 150 b. . . 150 n to the heat-transferelements 110 a, 110 b. . . 110 n can have an inlet fluid coupler 230 a,230 b. . . 230 n positioned at a distal end of the fluid conduit. Theinlet fluid coupler 230 a, 230 b. . . 230 n can be configured to couplethe respective fluid conduit to the distribution manifold 210.Similarly, the fluid conduit 172 a, 172 b. . . 172 n extending from therespective outlet 140 a, 140 b. . . 140 n of the heat-transfer elements110 a, 110 b. . . 110 n can have an outlet fluid coupler 240 a, 240 b. .. 240 n positioned at a distal end of the fluid conduit. The outletfluid coupler 240 a, 240 b. . . 240 n can be configured to couple therespective fluid conduits to the collection manifold 220.

In some embodiments, each respective inlet fluid coupler 230 a, 232 b. .. 230 n is configured sufficiently differently from the respectiveoutlet fluid couplers 240 a, 240 b. . . 240 n so as not to beinterchangeable with each other. Such non-interchangeable inlet andoutlet fluid couplers can reduce the likelihood that a user mightinadvertently connect an inlet fluid coupler to the collection manifold220 or an outlet fluid coupler to the distribution manifold 210. Each ofthe respective fluid couplers can be configured as a dripless quickconnect coupler, as described above.

Component heat-exchange modules 120 a, 130 a can be instrumented withone or more sensors configured to observe a relevant physical parameterassociated with the respective heat exchange module and to emit a signalcorresponding to the observed physical parameter. Signals emited by sucha sensor can be conveyed wirelessly to a receiver or on a wire to a bus.As described below, the manifold module 200 can include such a bus, anda signal wire extending from and corresponding to one or more sensorsrelating to each heat exchange module can be electrically coupled tosuch a bus, as by matingly engaging an electrical connector element onthe wire with an electrical connector element on the bus.

Manifold Module

As noted above and shown in FIG. 7, a manifold module 200 can have adistribution manifold and/or a collection manifold. The manifold module200 can include a body, or member, defining an elongate bore defining amanifold. The elongate bore can terminate within the body, defining anelongate recess having an opening 211, 221 at one end. A plurality oftransverse bores can extend inwardly of the construct and intersect theelongate bore, defining a plurality of transverse openings to theelongate bore. The construct can be formed of any suitable material orcombination of materials. In some embodiments, the construct can have aunitary construction, and in other embodiments, the construct has amulti-piece construction.

The elongate bore can define a distribution manifold 210 configured todistribute a flow of a working fluid among a plurality of heat-transferelements 110 a, 110 b. . . 110 n. For example, the opening 211 at theend of the elongate recess can define a fluid inlet, and each of theplurality of transverse openings 231 a, 231 b. . . 231 n can define arespective fluid outlet. An inlet to each respective heat-transferelement 110 a, 110 b. . . 110 n can be fluidicly coupled to acorresponding one of the transverse openings. With such a configuration,each of the heat-transfer elements can be fluidicly coupled to the otherheat-transfer elements in parallel.

The elongate bore can define a collection manifold 220 configured tocollect a flow of a working fluid among the plurality of heat-transferelements. For example, the opening at the end of the elongate recess candefine a fluid outlet 221, and each of the plurality of transverseopenings 242 a, 242 b. . . 242 n can define a respective fluid inlet tothe collection manifold. An outlet of each respective heat-transferelement 110 a, 110 b. . . 110 n can be fluidicly coupled to acorresponding one of the transverse openings. With such a configuration,each of the heat-transfer elements is fluidicly coupled to the otherheat-transfer elements in parallel.

In some instances, a given member can define a first elongate boreconfigured as a distribution manifold and a second elongate boreconfigured as a collection manifold. Such a construct is sometimesreferred to as a manifold module 200. The construct can be formed of anysuitable material or combination of materials. In some embodiments, theconstruct can have a unitary construction, and in other embodiments, theconstruct has a multi-piece construction.

Each opening 211, 221, 231, 241 in the manifold module can have acorresponding fluid coupler 332, 311, 230, 240. Each respective fluidcoupler can be configured as a dripless quick connect coupler of thetype described above.

As noted above, the fluid couplers corresponding to the distributionmanifold 210 and the fluid couplers corresponding to the collectionmanifold 220 can be configured sufficiently differently from each otherso as not to be interchangeable with each other (e.g., they can be“keyed” differently from each other). Such non-interchangeabledistribution and collection fluid couplers can reduce the likelihoodthat a user might inadvertently couple an inlet to a heat-transferelement to the collection manifold and an outlet from a heat-transferelement to the distribution manifold.

Coolant Heat-Exchange Module

In the context of a cooling system for rack mountable servers, anenvironmental coupler can have a coolant heat-exchange module. Suitablecoolant heat exchange modules can be passive (e.g., the coolant heatexchange module 300, shown in FIG. 6) or active (e.g., can include a“system” pump, as shown by way of example in FIG. 6B).

As shown in FIGS. 1, 5 and 9, the coolant heat-exchange module 300 canbe configured to exchange heat between the equipment heat-transfermodule 12 and an environment 16. For example, the coolant heat-exchangemodule 300 can have an environmental coupler 15 configured to exchangeheat between a working fluid in the equipment heat-transfer module 12and an environmental working fluid, such as, for example, a facility'swater supply 162, 16 b.

Referring to FIG. 6, an inlet 310 to the coolant heat-exchange module300 can be fluidicly coupled to an outlet 321 from the collectionmanifold 320. An inlet 315 a to a working-fluid reservoir 315 can befluidicly coupled downstream of the inlet 310, and an outlet 315 b fromthe reservoir 315 can be fluidicly coupled to an inlet 316 a to a stopvalve 316, sometimes also referred to as a shut-off valve. (The shut-offvalve can be closed to prevent the working fluid from being pumped outof or draining from the equipment heat-transfer module 12, e.g., in theevent of a leak.)

The environmental coupler 15 can be configured as a plate heat exchangeror as any other suitable liquid-liquid heat exchanger. For example, afirst inlet 321 a to the environmental coupler 15 (e.g., a plate heatexchanger) can be fluidicly coupled to the outlet 316 b of the stopvalve 316. A first fluid conduit 321 can extend between the first inlet321 a to the environmental coupler 15 and a first outlet 321 b from theenvironmental coupler, allowing the working fluid from the equipmentheat exchange module 12 to pass through the environmental coupler 15 andexchange heat with, e.g., an environmental fluid passing through asecond conduit 322 in the coupler 15.

A second inlet 322 a to the environmental coupler 15 can be fluidiclycoupled to a supply 16 b (FIGS. 1, 5 and 8) of an environmental workingfluid (e.g., a cool-water source). The second fluid conduit 322 canextend between the second fluid inlet 322 a and a second outlet 322 b,allowing the environmental working fluid to pass through theenvironmental 15 coupler and exchange heat with the working fluid of theequipment heat exchange module 12.

The first outlet 321 b (e.g., corresponding to the working fluid of theequipment heat-exchange module 12) can be fluidicly coupled to a checkvalve 325 (325 a, 325 b). The check valve 325 can prevent the workingfluid in the equipment heat exchange module 12 from reversing a flowdirection.

A proportional valve (not shown) can control a flow rate of theenvironmental working fluid, controlling the rate at which theenvironmental working fluid is permitted to flow through theenvironmental coupler 15. Thus, the proportional valve can control arate of heat transfer between the equipment heat exchange module 12 andthe environmental working fluid. As well, the respective pumps in theequipment heat exchange module 12 can be controlled to increase ordecrease the flow of working fluid through the environmental coupler 15and thereby control a rate of heat transfer with the environmentalworking fluid.

Controlling the flow rate of each respective working fluid through theenvironmental coupler 15 can also effectively control a temperature(e.g., a temperature of an exposed surface) of the environmentalcoupler. By controlling a temperature of the environmental coupler 15, auser can prevent, or substantially prevent, condensation from forming onor around the environmental coupler 15 by maintaining the temperature ofthe environmental coupler above the dew point.

Performance Examples

Presently disclosed systems can provide unrivaled cooling capacity andcost savings. For example, some disclosed systems can outperform otherliquid cooling solutions in today's data center market segment by aconsiderable margin. Recent testing has shown that presently disclosedsystems can provide a number of unprecedented benefits in the datacenter environment, from decreased operating expenditures tofacilitating increased rack densities. For example,

-   -   1. A flow rate of less than about 5 L/min (e.g., between about        4.5 L/min and about 5.5 L/min) of about 10C (e.g., between about        9C and about 11C) facility water: presently disclosed systems        represent the first liquid cooling solution to be so effective        that even at less than about 5 L/min, more than about 10 kW        (e.g., between about 9 kW and about 11 kW) of total CPU power        can be suitably cooled. This represents dramatic reductions in        facility water usage and represents substantial cost savings        compared to water usage and operating costs associated with        conventional liquid cooling systems.    -   2. A flow rate of about 30 L/min (e.g., between about 27 L/min        and about 33 L/min) of about 10C facility water: presently        disclosed systems can facilitate unparalleled cooling of high        rack densities, e.g., more than about 45 kW (e.g., between about        40 kW and about 50 kW) of heat can be dissipated at a relatively        low flow rate of about 30 L/min.    -   3. A flow rate of about 30 L/min of about 50C (e.g., between        about 45C and about 50C) facility water: presently disclosed        systems can provide suitable cooling using relatively low flow        rates and relatively hot water compared to conventional liquid        cooling systems, e.g., some presently disclosed systems can        suitably cool more than about 10 kW per rack with relatively hot        water (e.g., water at a temperature of about 50C) using a flow        rate of less than about 30 L/min. This translates to incredible        operational cost savings, including by elimination of chillers        (representing up to about 35% of total cooling costs), free-air        cooling, throttled down CRAC/CRAH systems, and less reliance on        server fans.

The unparalleled cooling performance of presently disclosed systems canallow a combination of increased density and decreased power usage thatsuit the specific needs of data center environment.

Facility water 16 b at 40° C. can be obtained in most climates with aneconomizer and without any supplemental refrigeration, chilling orcooling towers, eliminating a substantial source of power consumptionthat most conventional data centers must live with when relying onconventional cooling technologies.

In another example, 77% of the power consumed by air cooling a 95 Wattthermal-design-power processor was eliminated when the processor wascooled to the same temperature with a heat exchange module of the typedescribed above. In this example, 14 Watts of power consumed by theconventional cooling system was eliminated, eliminating about 5% of thetotal power consumed by the operable server (e.g., as measured at aninput to the server's power supply).

The cooling techniques described above greatly improve the coolingdensity that can be achieved for rack-mounted servers. Improved coolingdensity, in turn, allows greater computational capacity within a givenvolume, and improves the cost-effectiveness and performance of a givenphysical location. Moreover, cooling heat sources in servers usingliquid cooling, the sources can be cooled independently of the air in adata center, reducing the load on the room air conditioning andeliminating a source of large expenses associated with operating aconventional data center.

Table 1, below, summarizes several examples of cooling performance thatcan be achieved using modular heat-transfer systems of the typedisclosed herein. Surprisingly, some modular systems have achieved acase-to-coolant thermal resistance of about −0.056° C./W. Such asurprisingly low thermal resistance is adequate for cooling two 150 Wattmicroprocessors in a 1U server without requiring any chilling orrefrigeration of a facility's water source. For example, with such a lowthermal resistance, facility water entering the environmental coupler 15at 40° C. is capable of cooling the two microprocessors to 51.5° C. and55.1° C., respectively.

The data shown in Table 1, below, is for a single heat-transfer element110 a having two heat exchange modules of the type disclosed in the '379Application fluidicly coupled to each other in series, as describedabove. Each of the heat exchange modules was thermally coupled to arespective one of the microprocessors.

Facility Water Temperature = 20° C. Facility Facility Inlet LiquidTemperature (° C.) 20.0 Facility Outlet Liquid Temperature (° C.) 27.2Facility Cooling Water Supply Flow (L/min) 25.2 Rack Plate HeatExchanger Thermal Resistance (° C./W) 0.00032 Total Power (W) 12600Servers per Rack 42 Manifold Outlet Coolant Temperature (° C.) 31.2Total Rack Coolant Flow (L/min) 25.2 Server CPU Power (W) 150 ServerInlet Coolant Temperature (° C.) 24.0 CPUs per Server 2 CPU 1 Cap (° C.)31.5 ECO 2 Flow Rate (L/min) 0.60 CPU 2 Cap (° C.) 35.1 Cap to CoolantThermal Resistance (° C.) 0.050 Facility Water Temperature = 30° C.Facility Facility Inlet Liquid Temperature (° C.) 30.0 Facility OutletLiquid Temperature (° C.) 37.2 Facility Cooling Water Supply Flow(L/min) 25.2 Rack Plate Heat Exchanger Thermal Resistance (° C./W)0.00032 Total Power (W) 12600 Servers per Rack 42 Manifold OutletCoolant Temperature (° C.) 41.2 Total Rack Coolant Flow (L/min) 25.2Server CPU Power (W) 150 Server Inlet Coolant Temperature (° C.) 34.0CPUs per Server 2 CPU 1 Cap (° C.) 41.5 ECO 2 Flow Rate (L/min) 0.60 CPU2 Cap (° C.) 45.1 Cap to Coolant Thermal Resistance (° C.) 0.050Facility Water Temperature = 40° C. Facility Facility Inlet LiquidTemperature (° C.) 40.0 Facility Outlet Liquid Temperature (° C.) 47.2Facility Cooling Water Supply Flow (L/min) 25.2 Rack Plate HeatExchanger Thermal Resistance (° C./W) 0.00032 Total Power (W) 12600Servers per Rack 42 Manifold Outlet Coolant Temperature (° C.) 51.2Total Rack Coolant Flow (L/min) 25.2 Server CPU Power (W) 150 ServerInlet Coolant Temperature (° C.) 44.0 CPUs per Server 2 CPU 1 Cap (° C.)51.5 ECO 2 Flow Rate (L/min) 0.60 CPU 2 Cap (° C.) 55.1 Cap to CoolantThermal Resistance (° C.) 0.050

System Monitors and Controllers

As shown in FIG. 9, some disclosed modular heat-transfer systems 12include one or more sensors 210 a, 210 b. . . 210 n configured tomonitor one or more respective physical parameters of the system, or anenvironment 16. Also, some disclosed modular heat-transfer systems 12include a controller configured to adjust one or more operatingparameters of the system at least partially responsively to a signalemitted by a sensor. Some disclosed control systems include a computingenvironment of the type shown in FIG. 10. Some computing environmentscomprise a server being cooled by the modular heat-transfer system.

Some disclosed modular heat-transfer systems 10 include one or moresensors configured to monitor one or more corresponding physicalparameter of the system. Such sensors can include, among others, atemperature sensor so positioned relative to a fluid conduit (e.g., aconduit 20, 30, 40) as to provide a signal corresponding to atemperature of a fluid within the conduit or a temperature of a surfaceof a component heat-exchange module 120 a, 120 b (FIG. 2), a pressuresensor so positioned as to provide a signal corresponding to a relativepressure difference between a static pressure in a working fluid and aselected reference pressure, a speed sensor (e.g., a tachometer)configured to provide a signal corresponding to a rotational speed of apump, a float sensor or other sensor configured to provide a signalcorresponding to a coolant level in a reservoir, and a humidity sensorconfigured to provide a signal corresponding to one or more of anabsolute humidity, a relative humidity, a wet-bulb temperature and adry-bulb temperature. Such signals can include any type of signalsuitable for conveying information, including wired and wirelesssignals, e.g., radio frequency (RF), infrared (IR), microwave andphotonic signals.

Some disclosed coolant heat-exchange modules 300 include a controller330. For example, such a controller 330 can be configured to adjust oneor more operating parameters of a corresponding modular heat-transfersystem 10 at least partially responsive to a signal emitted by a sensorin response to a detected measurement of a physical parameter, e.g., ofthe system or of the environment. Such a controller 330 can also beconfigured to emit a signal 331 (FIG. 9) containing information relatedto a sensed operational parameter of the system 10. Such an emittedsignal can be received by a remote receiver (or by a server being cooledby the system 10), and an administrator can be alerted when an observedoperational parameter falls outside of a selected range (e.g., when anover temperature condition is detected).

In some instances, the working fluid heat exchanger module can include astop valve 316 being electrically actuatable between an open and aclosed position. The valve 316 can be configured to prevent circulationof the working fluid among the coolant heat-exchange module 300, themanifold module 200 and the array 100 of heat-transfer elements 110 a,110 b. . . 110 n when the valve is in the closed position.

The valve 316 can be operatively coupled to the controller. For example,the controller can be capable of actuating the valve by transmitting anactuation signal to the valve. The actuation signal can be transmittedat least partially responsively to a signal emitted by one or more ofthe sensors (e.g., a leak detector, a dew-point sensor).

Some disclosed modular heat-transfer systems include a computingenvironment, as shown in FIG. 10. Some computing environments areconfigured to translate an electrical or other signal from a sensor intoa user-recognizable form (e.g., by presenting a graphical display of atemperature, a pressure or a pump speed, or by invoking an audiblealarm). Some computing environments are configured as a controller foradjusting one or more operating parameters of the modular heat-transfersystem, as described above. In the context of rack-mountable servers,such a computing environment can include one or more of the serversbeing cooled by the respective heat-transfer elements.

Computing Environments

FIG. 10 illustrates a generalized example of a suitable computingenvironment 1100 in which described methods, embodiments, techniques,and technologies may be implemented. The computing environment 1100 isnot intended to suggest any limitation as to scope of use orfunctionality of the technology, as the technology may be implemented indiverse general-purpose or special-purpose computing environments. Forexample, the disclosed technology may be implemented with other computersystem configurations, including hand held devices, multiprocessorsystems, microprocessor-based or programmable consumer electronics,network PCs, minicomputers, mainframe computers, and the like. Thedisclosed technology may also be practiced in distributed computingenvironments where tasks are performed by remote processing devices thatare linked through a communications network. In a distributed computingenvironment, program modules may be located in both local and remotememory storage devices.

With reference to FIG. 10, the computing environment 1100 includes atleast one central processing unit 1110 and memory 1120. In FIG. 10, thismost basic configuration 1130 is included within a dashed line. Thecentral processing unit 1110 executes computer-executable instructionsand may be a real or a virtual processor. In a multi-processing system,multiple processing units execute computer-executable instructions toincrease processing power and as such, multiple processors can berunning simultaneously. The memory 1120 may be volatile memory (e.g.,registers, cache, RAM), non-volatile memory (e.g., ROM, EEPROM, flashmemory, etc.), or some combination of the two. The memory 1120 storessoftware 1180 that can, for example, implement one or more of theinnovative technologies described herein. A computing environment mayhave additional features. For example, the computing environment 1100includes storage 1140l one or more input devices 1150, one or moreoutput devices 1160, and one or more communication connections 1170. Aninterconnection mechanism (not shown) such as a bus, a controller, or anetwork, interconnects the components of the computing environment 1100.Typically, operating system software (not shown) provides an operatingenvironment for other software executing in the computing environment1100, and coordinates activities of the components of the computingenvironment 1100.

The storage 1140 may be removable or non-removable, and includesmagnetic disks, magnetic tapes or cassettes, CD-ROMs, CD-RWs, DVDs, orany other medium which can be used to store information and which can beaccessed within the computing environment 1100. The storage 1140 storesinstructions for the software 1180, which can implement technologiesdescribed herein.

The input device(s) 1150 may be a touch input device, such as akeyboard, keypad, mouse, pen, or trackball, a voice input device, ascanning device, or another device, that provides input to the computingenvironment 1100. For audio, the input device(s) 1150 may be a soundcard or similar device that accepts audio input in analog or digitalform, or a CD-ROM reader that provides audio samples to the computingenvironment 1100. The output device(s) 1160 may be a display, printer,speaker, CD-writer, or another device that provides output from thecomputing environment 1100.

The communication connection(s) 1170 enable communication over acommunication medium (e.g., a connecting network) to another computingentity. The communication medium conveys information such ascomputer-executable instructions, compressed graphics information, orother data in a modulated data signal. The data signal can includeinformation pertaining to a physical parameter observed by a sensor orpertaining to a command issued by a controller, e.g., to invoke a changein an operation of a component in the system 10 (FIG. 1).

Computer-readable media are any available media that can be accessedwithin a computing environment 1100. By way of example, and notlimitation, with the computing environment 1100, computer-readable mediainclude memory 1120, storage 1140, communication media (not shown), andcombinations of any of the above.

Other Exemplary Embodiments

The examples described above generally concern modular heat-transfersystems configured to exchange heat between a region of relativelyhigher temperature and a region of relatively lower temperature. Otherembodiments than those described above in detail are contemplated basedon the principles disclosed herein, together with any attendant changesin configurations of the respective apparatus described herein.Incorporating the principles disclosed herein, it is possible to providea wide variety of modular systems configured to transfer heat. Forexample, disclosed systems can be used to transfer heat to or fromcomponents in a data center, laser components, light-emitting diodes,chemical reactions, photovoltaic cells, solar collectors, and a varietyof other industrial, military and consumer devices now known andhereafter developed. Moreover, systems disclosed above can be used incombination with other heat-transfer systems, such as thermoelectriccoolers, refrigeration systems, and systems using air cooling ofperipheral components, as but several from among many possible examples.

Directions and references (e.g., up, down, top, bottom, left, right,rearward, forward, etc.) may be used to facilitate discussion of thedrawings but are not intended to be limiting. For example, certain termsmay be used such as “up,” “down,”, “upper,” “lower,” “horizontal,”“vertical,” “left,” “right,” and the like. Such terms are used, whereapplicable, to provide some clarity of description when dealing withrelative relationships, particularly with respect to the illustratedembodiments. Such terms are not, however, intended to imply absoluterelationships, positions, and/or orientations. For example, with respectto an object, an “upper” surface can become a “lower” surface simply byturning the object over. Nevertheless, it is still the same surface andthe object remains the same. As used herein, “and/or” means “and” or“or”, as well as “and” and “or.” Moreover, all patent and non-patentliterature cited herein is hereby incorporated by references in itsentirety for all purposes.

The principles described above in connection with any particular examplecan be combined with the principles described in connection with any oneor more of the other examples. Accordingly, this detailed descriptionshall not be construed in a limiting sense, and following a review ofthis disclosure, those of ordinary skill in the art will appreciate thewide variety of fluid heat exchange systems that can be devised usingthe various concepts described herein. Moreover, those of ordinary skillin the art will appreciate that the exemplary embodiments disclosedherein can be adapted to various configurations without departing fromthe disclosed principles.

The previous description of the disclosed embodiments is provided toenable any person skilled in the art to make or use the disclosedinnovations. Various modifications to those embodiments will be readilyapparent to those skilled in the art, and the generic principles definedherein may be applied to other embodiments without departing from thespirit or scope of this disclosure. Thus, the claimed inventions are notintended to be limited to the embodiments shown herein, but are to beaccorded the full scope consistent with the language of the claims,wherein reference to an element in the singular, such as by use of thearticle “a” or “an” is not intended to mean “one and only one” unlessspecifically so stated, but rather “one or more”. All structural andfunctional equivalents to the elements of the various embodimentsdescribed throughout the disclosure that are known or later come to beknown to those of ordinary skill in the art are intended to beencompassed by the features described and claimed herein. Moreover,nothing disclosed herein is intended to be dedicated to the publicregardless of whether such disclosure is explicitly recited in theclaims. No claim element is to be construed under the provisions of 35USC 112, sixth paragraph, unless the element is expressly recited usingthe phrase “means for” or “step for”.

Thus, in view of the many possible embodiments to which the disclosedprinciples can be applied, it should be recognized that theabove-described embodiments are only examples and should not be taken aslimiting in scope. We therefore reserve all rights to the subject matterdisclosed herein, including the right to claim all that comes within thescope and spirit of the foregoing description.

1. A modular heat-transfer system comprising: an array having at leastone heat-transfer element defining an inlet and an outlet and beingconfigured to transfer heat to a working fluid from an operable elementcorresponding to the at least one heat-transfer element, or to transferheat from a working fluid to an operable element corresponding to the atleast one heat-transfer element; a manifold module having a distributionmanifold and a collection manifold, a decoupleable inlet couplercorresponding to each respective inlet of each respective heat-transferelement in the array, wherein the respective inlet coupler is configuredto fluidicly couple the distribution manifold to the inlet of therespective heat-transfer element; a decoupleable outlet couplercorresponding to each respective outlet of each respective heat-transferelement in the array, wherein the respective outlet coupler isconfigured to fluidicly couple the outlet of the respectiveheat-transfer element to the collection manifold; and an environmentalcoupler configured to receive the working fluid from the collectionmanifold, to transfer heat to an environmental fluid from the workingfluid or to transfer heat from an environmental fluid to the workingfluid, and to discharge the working fluid to the distribution manifold.2-3. (canceled)